"Let's Not Meet" is the title of an online subforum on Reddit where users submit true scary stories of encounters with strangers. Many of these stories are narrated on YouTube which is where the writer/director drew inspiration from.
The director's favorite horror film "Jeepers Creepers", served as an inspiration for "Let's Not Meet". The scene in which one of the characters suddenly disappears, leaving behind only a flashlight, was a nod to a similar scene in Jeepers Creepers 2 when one of the coaches is snatched up by The Creeper.
The appearance of the film's primary antagonist was inspired by a true story the writer/director heard from an African missionary. She had a disturbing encounter with a man covered head to toe - coat, scarves, turban, sunglasses, and gloves - despite the African heat. Locals later told her the "man" she had seen was The Devil.